Referring to FIG. 11, a toolbox includes two shells 40 connected with each other. Each shell 40 includes a space 41 defined therein and two series of tenons 42 formed thereon. The space 41 is located between the series of tenons 42. Several tool holders 20 are put in the space 41 so as to hold tools. Each end of each tool holder 20 defines at least one mortise 21 for receiving at least one of the tenons 42. The tool holders 20 lie on the shells 40. The tools also lie on the shells 40. However, it is inconvenient to take the tools from the tool holders 20 in such a position. Furthermore, the tenons 42 cannot be securely engaged with the mortises 21. The tool holders 20 can easily be detached from the shells 40 because of vibration. Thus, the tool holders 20 may fall on the ground when the toolbox is opened, and the tools may be detached from the tool holders 20 and dispersed. Therefore, the tool holders 20 and the tools may be damaged.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.